One of the ironclad beliefs among education reformers back in the day was the certainty that the achievement gap was caused, at least in part, by a teacher-quality gap. As articulated in the Education Trust’s landmark 1998 white paper Good Teaching Matters, by any measure you could come up with, the most qualified teachers were in the most-affluent schools, while the least qualified worked in the highest-poverty ones. This, more than anything else, is what we meant by “under-resourced” schools and was the result of our inequitable funding system, combined with HR systems and collective bargaining agreements that put the preferences of adults over the needs of kids—especially low-income students and students of color.